moore



Jan. 5, 1965 R. w. MOORE 3,163,967

VIBRATORY FINISHING Filed Feb. 13, 1964 e Sheets-Sheet 1 .F z mi.

INVENT OR Ralph WM'oore w gwmw g ATTORNEY Jan. 5, 1965 R. w. MOORE VIBRATORY FINISHING 6 Sheets-Sheet 2 Filed Feb. 15, 1964 INVENTOR more BY ATTORNEYS Jan. 5, 1965 R. w. MOORE 3,163,967

- VIBRATORY FINISHING Filed Feb. 15, 1964 6 Sheets-Sheet 3 llllllllll .r///////r IN VEN 1 OR ATTORNEYS Jan. 5, 1965 R. w. MOORE 3,163,957

VIBRATORY FINISHING Filed Feb. 13, 1964 6 Sheets-Sheet 4 11011 1001: l I 530.1) I 53/ INVENTOR 34m more ATTORNEYS Jan. 5, 1965 R. w. MOORE VIBRATORY FINISHING 6 Sheets-Sheet 5 Filed Feb. 13, 1964 INVENTOR Ralph W Moore BY (44% M xrrorz Jan. 5, 1965 R. w. MOORE 3, 67

VIBRATORY FINISHING Filed Feb. 15, 1964 6 Sheets-Sheet 6 INVENTOR Ralph WMoore BY I United States Patent Ofice 3,163,967 Fatented Jan. 5., 1965 3 163967 VIERATORY FINESHENG Ralph W. Moore, Hagerstown, Md, assignnr to The Pangborn Corporation, Hagerstown, Md, a corporation of Deiaware Fiied Feb. 13, 1964, Ser. No. 344,763 Claims priority, application Great Britain, lien. 23, 1%1, 2,575/61 5 Claims. ill. 51163) This invention relates to vibratory finishing, more particularly the type of vibratory or gyratory finishing suitable for treatment of work pieces of metal or the like for the purpose of deburring, descaling, cleaning, polishing, burnishing, rounding corners and edges, etc.

This application is a continuation-in-part of application Serial No. 168,146 filed January 23, 1962, which in turn is a continuation-in-part of application Serial No. 4,908 filed January 27, 1960, and now US. Patent 3,063,- 207 granted November 13, 1962.

The use of vibration or gyration for the above purpose has been known for some time. However, machines built for these purposes have been relatively complicated and cumbersome as well as somewhat awkward to use when adapted for variable loading.

Among the objects of the present invention is the provision of novel equipment and techniques for the above type of finishing that simplifies the handling of widely varying loads and reduces the cost of such treatment.

The above as Well as additional objects of the present invention will be more clearly understood from the following description of several of its exemplifications, reference being made to the accompanying drawings wherein:

FIG. 1 is a front view partially in section of an apparatus representative of the present invention;

FIG. 2 is a side view partially in section of the apparatus of FIG. 1;

FIG. 3 is a detail on an enlarged scale and partially in section of a modification of one of the support elements of the apparatus of FIGS. 1 and 2;

FIG. 4 is a view similar to FIG. 3 shown with the support elements in olfset position;

FIG. 5 is a detail on an enlarged scale and partially in section of a further modification of one of the support elements;

FIG. 5a is a detail on an enlarged scale and partially in section of a still further support arrange for a vibratory apparatus;

FIG. 6 is a detail of a modified gyration support for the apparatus of FIGS. 1 and 2;

FIG. 7 is another detail illustrating an optional base construction in the apparatus of the present invention;

FIGS. 8 and 9 are perspectives showing suitable cover arrangements for the apparatus of FIG. 1;

FIGS. 10 and 11 are enlarged perspectives in detail and partially sectioned of a portion of a drive connection for the apparatus of the present invention;

FIG. 12 is a view similar to FIG. 7 of another optional base construction; and

FIG. 13 shows an arrangement for constructing the apparatus of the present invention.

According to the present invention the vibratory finishing apparatus has a container for the work articles, and vibrating structure connected to gyrate the container. The container is supported by air cushions as in the above-identified parent applications. These air cushions are preferably arranged elfectively below the container, preferably with four or more such cushions in symmetrically spaced relationship although fewer can be used if desired. It is found particularly helpful, however, to have at each supported location an air cushion effectively below the container and at least one pre-loading device such as another air cushion or spring effectively above the container, since this is found to provide better control over the operation of the apparatus and to increase its loading range. A cushion is effectively below the container when the container or a supporting member secured to the container rests on top of the cushion. Conversely a cushion or spring is effectively above the container when the container or a supporting member secured to the container depends from the cushion.

Each air cushion can be in the very simple form of a pair of substantially rigid open cups with their open sides facing each other and held apart by a resilient hollow airfilled tube having open ends secured in the respective cups. It is also advantageous to have the air cushions connected to a source of air under variable pressure so that the pres sure in the air cushions can be altered to thereby vary the resiliency that the cushions provide. All the lower air cushions can, for example be connected to one source of air, and an upper set of air cushions to another source of air so that the support of each location can be changed through an extremely wide range of resiliency and stiffness. This controlled variation in resiliency or in support is also accomplished by employing a preloading spring device such as a coil spring in general opposition to the lower supporting cushion.

Although at each support the air cushions and preloading spring can be provided in pairs, one above and one below the container support, the upper ones can be offset or some even omitted entirely. The support for the container conveniently carries the vibrating drive structure and can have a base provided with an additional set of cushions by which it is supported on a fioor or the like.

Referring now to the drawings, FIGS. 1 and 2 show a vibratory treatment apparatus having a generally troughshaped container 5% held on a table 520 as by means of bolts 14 through the table top sheet 522. Feet 550 secured as by welding to the underside of the container provide convenient fiat surfaces at their lower portions for engagement against the table top 522. The table is vibrated by means of a shaft 18 having an eccentric weight 521 secured thereto and journalled between bearings 524 and 526 rigidly attached to the table as by means of the plates 533 and 534 welded to the underside of the table. Skirts 531 and 532 depending from the side edge of the table and also fastened to the table by welding, help to greatly increase the rigidity of the connection to the vibrating drive. The eccentric Weight can be replaceably attached to shaft 18 as by bolts so that different weights can be used for modifying the magnitude of vibration.

The air cushion support is shown as provided by upper and lower flanges 518 and 544 secured against the inner surfaces of the sheets 504 and carrying horizontally extending shelves 514% that are received between the flanges of supporting sheets 564 that encircle the table. Sheet 522 of the table is joined to the flange 518 below it by an air cushion 42, and is also similarly joined by an air cushion 40 to the flange above it.

FIGS. 1 and 2 employ a tilt framework 538 made of a pair of traverse channel beams secured to and connected by side sheets 5%. These side sheets have flanged longitudinal edges for added stifi ness and are also bent inwardly near their lower portion to further increase their rigidity and protect the interior somewhat against splashing from the floor. The outer faces of the beams 5% are covered by end panels 506 which extend over the entire space between the end sheets and also rise to a height well above them. The margins of the end panels are also flanged for strength. A similar intermediate panel 598 is secured between the side sheets and is reinforced as by can also be provided to facilitate the filling. Inasmuch as rubber will vulcanize better to certain surfaces such as brass, the inside surface of the container can be plated with a thin layer of brass. On the other hand, the surface of the mold is preferably coated with a thin layer of a mold release such as silicone oils.

Instead of rubber, plastics such as polyethylene, polyvinylchloride, polyurethanes and epoxy resins, can be used. These can be plasticized or unplasticized. The absence of plasticizer makes the plastics somewhat more abrasionresistant but on the other hand, the presence of plasticizer makes them somewhat more resilient.

The molding operation can also be carried out with the container in the right-side-up position, in which event no opening is needed in the bottom of the container and the openings can then be merely provided at the top of the internal mold. The internal mold can also be made in detachable sections so as to render it easier to remove when the molding operation is completed. Instead of molding the container lining in place in the container, it can also be separately molded between removable mold shells and then cemented or vulcanized in the container. With such an arrangement the apparatus of the present invention need not have a removable container. Instead, the container can be made integral with the table.

The apparatus of FIG. 1 has a vibration frequency measuring device shown as a tachometer generator 573 held on a shelf 571 mounted against the inner surface of panel 506. This generator has a shaft connected as by a simple coupling such as a short length of rubber or resilient plastic tubing 575, to a stub shaft extending from the jackshaft pulley. A conductor cable supplies the output of the tachometer generator to a conveniently located meter on which the output is read on an indicator scale. Other systems can also be used for measuring the rotational speed of the vibrating shaft or can even measure the vibration with a series of reeds mounted for free vibration with the individual reeds having natural periods of vibration adjusted to be at graded intervals over the desired operating range. The reed that shows the strongest vibration when the assembly of reeds is mounted anywhere on the apparatus, indicates the frequency at which the apparatus is operating.

The equipment can also be provided with a safeguard against difiiculties that could result from an attempt to operate the vibrating drive when the container is tilted toward unloading position. For this purpose FIG. 1 shows a block 577 secured to the outer face of panel 5% and a cooperating switch 5'79 on the adjacent supporting pier. These two components are so located that when the container is upright in its operating position the block trips the switch 579 closed, thereby establishing an electrical circuit used in energizing the vibrating drive. In all other positions of the container the block is disengaged from the switch so that vibration cannot be carried out.

The air cushions of the present invention can be constructed in different ways. They can for example be in the form of pneumatic cylinders with movable pistons as in the tilt cylinders referred to above. Such an air cushion has practically no resilient structural elements. The air cushions can also be of all-resilient construction, as by making them of hollow balls of resilient material such as rubber or plastic, and mounting the balls between spherical sockets on the table and tilt frame anchorages. Balls of this type can be cemented or vulcanized in their sockets, or they can be fastened there by bolts extending through the wall of the ball to its interior where they can be threaded into inserts. The air cushions can also have combinations of resilient and non-resilient elements in forms other than those illustrated, but the illustrated construction is preferred because it is simple to manufacture, assemble, use, and maintain.

The air cushions can also be used to suspend the container. By having such cushions effectively above the container, and no supports effectively below the container,

the container is suspended in such a way as to gyrate effectively when actuated by any of the vibrating drives referred to above. In this type of combination the ball type cushion is very suitable inasmuch as it easily withstands the tensions developed by the suspended load. Pneumatic cylinders connected between the container and a support are also suitable for such suspended service, particularly when the connections are ball-and-socket joints that allow practically unrestrained gyration.

According to the present invention, air cushions can be used in conjunction with conventional spring supports. By way of example, a container supported on the usual combination of coil and leaf spring mounts, can have a set of air cushions effectively above the container and holding it down with a controllable force. Adjusting the pressure in the cushionscan then vary the downward force and thereby adjust the height of the container. This will simplify the construction as well as prolong the life of a flexible drive connection or the like.

Any mechanical spring such as a block of resilient rubber can be used in place of the coil and leaf springs of the foregoing combination.

Driving of shaft 18 to cause gyration of the container can be effected as by means of an electric motor carried by the table, the framework, or any other convenient manner. One highly effective arrangement which reduces the number of components as well as the total mass of the vibratory members is to mount such a motor on the tilting framework. In FIG. 1 such a motor is shown at 68 carried by a panel 508 depending from the framework alongside the table 520. A drive connection such as a variable ratio pulley combination such as shown in FIG. 10 connects the motor with a jackshaft 74 journalled in bearings 542 held on a shelf 544. The jackshaft is in turn coupled to the vibrating shaft 18 by means of a flexible drive coupling 82 as shown having an annularly positioned flexible trough-shaped member 84 clamped between drive discs, keyed to shafts 7 and 18.

The air cushions can be of relatively simple construction such as indicated in above-mentioned US. Patent 3,063,207, having an upper cup and a lower cup of rigid material such as metal, with a flexible open ended tube of a material such as rubber or rubber impregnated fabric, connecting them together, the respective ends of the tube being secured in the individual cups. To facilitate this securing the lips of the cups can be turned in, and the ends of the tube molded with an outward flare that mates with the turned-in lips. These tube ends can also be provided with a beading of metal or the like to more securely hold them in place. The central portions of the tube can also be molded with at least a small enlargement so as to assure proper positioning when the-cushions are-deflated. The cups can also be equipped with a suitable fitting 96 such as shown in FIG. 6 to provide a connection to the interior of the cushion and receiving an air line such as conduit 8.

A single main air supply can, for example, be conveniently mounted on the piers 54 and connected by separate adjustable pressure reducing valves to the lines 98, llflil. The same air supply can also be used to operate tilting cylinder 58.

The tilting of the container can be arranged to take place in either direction around the framework pivots 59. In fact, dual tilting can also be provided so that the container can be tilted in one direction as for dumping the work, and in the opposite direction for other purposes such as rinsing the work or the container. The container 5% is shown as provided with an internal liner 1% (FIG. 3) of a resilient material such as natural or synthetic rubber which can be vulcanized in place.

The electric motor 68 is illustrated in FIGS. 1 and 10 as of the pancake type so as to enable more compact positioning of the various parts within the framework and also reduce the size of the framework. Adjustment for pulley tension is conveniently arranged by having the arcane? motor support slidably mounted for vertical movement on the panel 568.

Jackshaft 74 can also be adjustably positioned vertically so as to stay within the operating tolerances of the coupling 82 insofar as any offset of the jackshaft from the vibration shaft 18 is concerned. The air cushion is arranged to compensate for changes in weight of container contents, and thereby keep vibrating shaft 18 at a height well within the limits of the drive coupling. in fact, the air cushions can be made to exactly compensate for changes in container loading.

The apparatus illustrated in FIGS. 1 and 2 is used by loading it with the work pieces as well as any other mate rials'that help in the vibratory treatment. These other materials are generally the same as those used in the wellknown barrel finishing of work pieces where the work is tumbled in a revolving barrel rather than vibrated or gyrated. Such additional materials include abrasive objects made of ceramic or metal and of such shape that they clean, polish, smooth or round off the work articles as desired. For some operations these abrasive objects can be omitted. In addition, liquids are generally used to help suspend particles that are removed from the work pieces, and keep them from becoming re-irnbedded in the work pieces. The liquids are generally aqueous and contain dispersing agents with or without soaps, and burnishing ingredients may also be added. Emulsions or solutions can be used, and where descaling is to be carried out, the liquid can also contain ingredients such as acids that dissolve the scale. The selection of the particular combination of abrasive media and liquids is well known to those skilled in the art and forms no part of the present invention. Reference is made to Metal Handbook, 1948 Edition, published by The American Society for Metals, Cleveland 3, Ohio, pages Bill to 305, as Well as ,U.S. Patents 2,318,581 and 2,464,486, for additional de tails in this respect.

The container can be filled very close to the top, generally within three inches or so, and the vibration mechanism immediately started. This causes the container to gyrate withrespect to its supports, and tms in turn causes the individual solids in the container to be rubbed against eachother and in addition also causes the entire contents of the container to circulate in more or less circular path around a center parallel to the vibrating shaft :28. For rough finishing operations, as well as those in which it is desired to markedly round off corners or edges, the air pressures in the respective air cushion can be adjusted so as to produce a large gyration amplitude, that is about /3; inch or more measured at the air cushions themselves. Changing the weight 521 on the eccentric shaft 18 provides even greater amplitude control.

Frequency control can be effected by changing the speed of the eccentric shaft 18, as by varying the drive ratio between the pulleys on the pulley drive 72. The pulleys can for instance have tapered belt-engaging surfaces with the respective surfaces movable with respect to the mating surface and mechanically controllable to give the pulleys variable diameters. By controlling the diameter of one pulley and having the halves of the second pulley spring loaded, the second pulley will automatically undergo diameter changesthat are induced by the belt tension changes caused by control changes in the first pulley, and the combined changes will give a new drive ratio. Both pulleys can also be directly controlled, if desired.

FIGS. and 11 illustrate one form of speed control arrangement in accordance with the present invention. The motor ebis here secured to a supporting panel 5% by bolts or studs '71 extending from the motor housing and passing through slots 73 in the plate. Nuts 75 and washers 77 clamp the bolts in place in any selected position along the slots. The shaft 79 of the motor is secured by a keyed drive to a pulley hub which in turn carries two separate pulley halves 83, S5 clamped in place as by split clamps 87. A groove 88 extending longitudinally of hub 31 on its outer surface mates with corresponding grooves 8%, hi in the respective pulley halves and together these grooves receive an adjusting screw 93. The threads of this screw are divided into two longitudinal portions, one left-handed and the other right-handed. The grooves in the respective pulley halves are similarly threaded, the groove 88 being unthreaded. Rotation of the screw, as by the Allen wrench 5 5, causes the pulley halves to move toward or away from each other, depending on the direction of screw rotation. The clamps 87 should be loosened to enable such motion of the pulley halves, and can then be tightened as by screws 97 extending through one end of each split ring and threaded into the opposite end. Adjustment of the pulley halves causes the belt, which has a fixed width, to fit in a correspondingly shifted portion of the tapered drive faces of the pulley halves thereby effectively changing the diameter of the motor pulley.

The cooperating pulley can be non-adjustable in which event all drive adjustments are accompanied by resetting of the position of the motor 68 along the grooves '73, or the cooperating pulley can be of the split spring-loaded type referred to above in which event all adjustments in the motor pulley cause correlative spreading or narrowing of the driven pulley without any change in motor position.

instead of having the pulley adjustment made only when the machine is stopped, a standard type of rotating pulley adjustment device can be used. For example, the drive pulley can have one of its halves equipped with a collar freely rotatable around the pulley hub and engaged with a manually adjustable slider fork connected to be adjusted while the pulley is rotating as well as while it is stopped. The other half of the drive pulley can be fixed in position, and the driven pulley can have a corresponding fixed half cooperating with a spring-loaded half to keep the belt center ali ned on both pulleys.

Speed changes in the vibrating frequency at which the apparatus is driven are also easily made by merely using a standard induction type A.C. winding arrangement in the drive motor, and supplying the motor with electrical power at a variable frequency. Thus a 60 cycle power supply to such a motor can drive it at 1800 r.p.m., whereas cycle power will drive it at /6 of 1800 or 1500 rpm. A generator having a controllable output frequency can then be used to change the vibrating frequency without mechanical change in the vibratory apparatus itself.

As pointed out above, when the air cushions are supplied in pairs above and below the container table, they need not have the individual cushions of each pair directly opposed. These cushions can be oiiset, if desired, and this offsetting is helpful in simplifying the mounting of the cushions. The additional air cushions used for supporting the base of the apparatus can be identical with the cushions illustrated in the figures, or they can be different in size and/or shape. The cushions used to support the table, or the container where a table is omitted, can also be varied in size and shape and where pairs of cushions are used in the individual cushions of each pair need not be identical. FIG. 6 shows an offset pair of table-supporting air cushions 4t), 42 each of different size, in the general arrangement of the construction of F168. 1 and 2.

FlGS. 3 and 4 show a useful modification of the supporting elements in which valved air cushions %A and lilB are employed in supporting position below table 520A and SZKFB. Coil springs l hllA and ldllB are mounted in preolading position above the table, and held in place by a nipple MBA and N213 respectively, attached by a bolt to brackets 545A and 545B attached to side sheet 5%. in FIG. 4 is shown a suitable offset arrangement for the coil spring liltiB and air cushion 46B.

FIG. 5 shows another modification of the supporting element in which valved air cushion 4 3C acts as a preloading device above coil spring 138C. A compression screw 198C initially adjusts the level of the table SZJC.

FIG. 5a has a vibratory container 5855i) supported on a table 520D in a manner similar to that of FIG. 4 using a set of air cushions 40D and offset coil springs 106D above them. The ends of coil spring 1003) are here secured to their supports by forming the supports with threaded engagement surfaces 110D in which about three or more turns of each coil end is threaded. This type of anchorage helps prevent chattering of the coil springs when the container is vibrated at some speeds, usually those well above the natural vibration frequency of the coil springs themselves.

Other mechanical springs including the resilient rubber blocks referred to above can be used in place of the coil springs of FIGS. 3, 4 and 5.

FIG. So also includes an amplitude-limiting arrangement for the container and table. A bar 539D fastened to the table or container is arranged to project out through an aperture 532D in an angled member 532]) secured to the framework 531 or in a reinforced section thereof. The aperture 532D can provide a space all around the bar suflicient to permit the bar to vibrate with the table through the usual range of vibratory amplitudes. Generally a /2 inch clearance is sufficient. This will also minimize the possibiltiy of damage to the air cushions in the event the pressure within them is suddenly released, for example should there be failure of the air pump or inadvertent opening of a vent valve. When this happens the small clearance of opening 532D will keep the air cushion from complete collapse. The bar 530D should be made sufficiently strong for the above purpose as by cutting it from a /2 inch thick steel plate. Also to keep the bar from pivoting on its mount it can be fixed in place by more than one bolt. It can, for example, be in the shape of a T with both arms of the T secured by spaced bolts and the leg of the T extending through the aperture 532D. The position of the bar in the aperture also makes a suitable height indicator for the container. Fuithermore it can be so co-related with the alignment of the flexible drive connection where one is used as at 82 in FIG. 1 that a misalignment will cause the rod 539D to hammer against the margin of aperture 532D when the work is being vibrated. This gives an audible warning of misalignment, and such a warning is not easily ignored.

It is preferred that the cushions be protected from mechanical damage as by mounting them internally of the outer Walls of the machine, according to the above instructions for example.

The vibrating apparatus of the present invention preferably has its base supported on a floor by additional air cushions. Such base cushions need not have their pressures readily adjustable, and they can be protected by surrounding the individual cushions with a pair of loosely inter-fitting sleeves, the inner one secured to the ground contact or floor plate, and the outer one secured to the machine base. Each sleeve should have its unsecured end spaced from the opposed portion of the base mounting so as to permit a small amount of motion between the base and the machine mounting plate. Also the outer sleeve can have its upper or secured end complete- -ly covered so as to be waterproof and thereby act as an umbrella to protect the cushion. The amount of movement permitted by the sleeves is very desirably arranged so that the sleeves reach the limit of their collapsed travel and firmly engage their opposing members to thereby support the entire apparatus, before the air cushion is completely deflated. This is helpful particularly for shipping and erection purposes, and minimizes the possibility of damaging the air cushion. A further improvement is to supply a resilient bumper on the unsecured end of one of the sleeves, prefer-ably the inner sleeve, so as to reduce the shock that might accompany rapid defla tion. The same bumper can also extend laterally to further absorb lateral deflection shocks. The unsecured end of the outer sleeve can be provided with a travel clearance somewhat greater than that of the inner sleeve so as 10 to keep the outer sleeve from engaging its collapsed stop and thereby avoid any pinching action.

FIG. 7 shows such a base support in which an air cushion 301 is fitted between the floor 303 and the bottom of pier 54, and is surrounded by an inner sleeve 395 standing up from the floor. The top of the inner sleeve carries a rubber bumper strip 307 and the sleeve itself is surrounded by an outer sleeve 309 depending from the bottom of the pier.

The work containers in accordance with the present invention can be used in uncovered condition as illustrated, or they can be provided with covers as for example to maintain a desired atmosphere in the work container or for the purpose of assisting with screening operations or rinsing operations. One very desirable form of cover has a tapered mounted clip along one edge for engaging an edge of the container, which edge may be flanged as also illustrated in FIGS. 8 and 9. The opposite edge of the cover can be provided with one or more toggle clamps or the like which can be secured to the cover and clamped against the edge of the container. The taper of the cover mounting clip is arranged so as to cam the cover against the open face of the container when the cover is slipped into position, and before the clamp is set.

Perforated covers when used for rinsing can be fitted over the container at the end of the vibration treatment or when the treatment goes from one stage to another and the liquid contents are to be replaced or removed. Perforated covers can be made of sheet material or of screening, held in a suitable framework and with the openings or screening of any desired mesh. FIGS. 8 and 9 show covers 411 of this type in which there is provided a screened passageway 413 as well as a hose connection 415 for filling or washing. This connection is desirably of the quick disconnect type that cooperates with the well-known quick disconnect hose fittings which seal the hose end but which automatically open the hose end when the fitting is mounted over the hose connection 415. A tapered mounting clip 417 is formed at one edge of the cover 411, and under the cover a fine screen 419 can be slipped as shown in FIG. 9, when the screen in the cover itself is too coarse for a desired screening operation. Toggle clamps 421 or other suitable fasteners can be used to lock the cover in place with or without the fine screen.

A fairly coarse mesh is suitable for general use and will keep work articles as well as most media particles from spilling out of the container when it is tilted for example. Finer meshes are sometimes needed for use with extremely small work pieces or small particles of gyrating media, and such fine screens can either be provided with their own frames or can be inserted under a coarser screen. The tapered clip arrangement permits the lifting of the main screen, the insertion of an auxiliary screen underneath, and the re-locking of the cover without detracting from the cover fastenings security.

Where the vibrating drive uses a motor separately mounted on the support that carries the container and its table, the pancake type of motor construction is an unusually eifective one, particularly when the pancake motor has a mounting flange along one face of the pancake. The motor can then be mounted in place by bolts or the like extended through bolt receiving apertures in the motor flange as well as in the wall to which the motor is mounted. The bolt receiving apertures in the wall can be elongated so as to be in the shape of slots and thereby allow adjustment of the motor position, or the slots can be in the motor flange for the same purpose. A feature of this construction is that the motor can be very simply adjusted by tilting the apparatus and permitting the motor to move under the influence of its own weight. Thus by simply loosening the motor fastening bolts when the apparatus is tilted toward the unloading position, the motor can be held in place by its drive belt, so that the proper belt tension is obtained, after which the mounting bolts are again clamped in place to secure the drive. To

1 1 change adjustments the apparatus with the motor bolts loosened is tilted toward operating position so as to permit the motor to slide down its mounting slots and loosen its belt. The belt can then be replaced if desired. Either or both of the belt pulleys can be adjusted when the belt is loosened.

A similar adjustment can be made with any flangemounted electric motor, that is a motor having a mounting flange extending perpendicularly to its shaft. If such motor is not of the pancake type, its axial length is rela tively long so that more room must be provided for it. This is no great drawback with vibrators in which the Work containers do not tilt, but tilting work containers are preferably held on the same framework that carries the motor and increasing the aXial length of a tilting frame- Work adds appreciably to'construction costs.

An electric motor drive for the vibrating mechanism makes a more eflicient power supply than any other type of drive, and vibrators generally require considerable power. The compactness and relatively low speed available with electric motors, together with. the adjustaoility of the speed also admirably suit such vibrators inasmuch as they generally operate in that range of speeds. Electric motors can be easily arranged to tilt with a tilting container-holding framework, and can be conveniently mounted in the interior of the framework with its leads and controls not interfering with the tilting. Moreover by isolating the electric motor from essentially all the vibration, it need not be of the relatively expensive vibration-proof type.

The moving of work articles along the vibrating container as for continuous flow treatment, is affected by the relationship of the eccentric shaft 18 with the longitudinal axis of the container. If the shaft is not exactly parallel to that axis, the vibration causes the container contents to move toward the container portions having the greaer amplitude of vibration. As little as 1 degree of angularity or skew will give a perceptible longitudinal or flow motion, and sometimes normal variations in manufacturing of the structural components have to be compensated for to avoid such motion. A skew of 2 or 3 degrees is very helpful in bringing about rapid flow motion, and this can be used to help discharge the container contents from one of its longitudinal ends. This action should be avoided with batch type operation Where it has the effect of segregating the work pieces as well as the media, in longitudinally localized strata.

The flow through the container can be arranged to take place without tilting the continuous-flow container, by utilizing the skew action. Furthermore, or in place of skew act-ion, the work flow will result from the mere loading of the container. As loading takes place, the contents of the container tend to overflow inasmuch as they are in a fluent condition, and the provision of a low spot at a desired location of the container rim will establish overflow there. The faster the loading, the faster the overflow thus caused. The skew action can be used to assist or retard the efiect of the loading.

Another feature of the present invention is that the air cushion supports lend themselves admirably to vibration or gy-r-ation at frequencies diflerent from the natural vibrating or gyrating frequency of the assembly. In fact, the vibratory finishing action is generally speeded up when the frequency is broughtto about 1500 cycles per minute and most machines Will have natural frequencies 'of the order of 900 or fewer cycles per minute.

The air cushions 'in the floor mounts sharply reduce the amount of vibration thatis transmitted to the door l2 and-fro motion. Because of the manner in which the vibrating table and container are supported, they undergo rotary vibrations with diflerent portions of the container as well as its contents moving through different rotary paths. This gyration gives better finishing as compared to simple to-and-fro linear vibration.

Another fair cushion support for the apparatus of the present invention is illustrated in H6. 12. in this construction the dual tube arrangement of FIG. 7 is used along with a clamping device to secure the components in place while the apparatus is being shipped from one location to another. For this purpose a set of spaced lugs 311 is secured as by Welding to the outer tube and studs 3135 extend through apertures in the lug-s and threadedly engage a plate 325 to which the lower tube is fastened. If desired, this threaded engagement can be with nuts 317 welded to the :top of the plate. Removable nuts 319 on the studs can then be threaded on the studs and engaged against the upper faces of the lugs to effectively clamp the upper tube to the lower tube. In clamped condition the apparatus can be crated and shipped without fear that the base air cushions will become disengaged from their mountings.

FIG. 12 also includes a resilient pad 32]; under the bottom plate 315 of the base. This pad which is conveniently a rubber sheet makes up for minor irregularities in the floor 32,2 upon which the base rests and provides much better vibration with less transmission of the vibrations to the floor. The pad need only be a inch thick slab of tough rubber such as is used in automobile tire tread, preferably with Waffled or dimpled faces. if desired, thicker rubber slabs can be used, and the rubber can be natural rubber or any synthetic rubber such as butadiene-styrene rubber, butyl rubber, neoprene or the like. The pad 321 can have one or more perforations aligned with corresponding perforations in base plate 315 so that a wire or the like can be threaed through the perforations to hold the pads in place during shipment of the apparatus. Alternatively, the pads can be cemented in place.

To keep from damaging the pads or the floor, the fasteners used to hold the air cushion 3631 in the supports of FIGS. 7 or 12 to the base plate should not project below the lower surface of the base plate. Fla-t head or other suitable fiush-f1tted or countersunk screws 324 can be used for this purpose, and can be threaded into blind nuts fitted within the air cushion.

While the container and its associated members, such as the table on which it is supported, can be elfectivcly gyrated with only a set of four air cushions supporting it, the use of opposed resilient forces such as the abovementioned preloading, helps to secure the desired vibration. Furthermore, the advantages contributed by the air cushions in simplifying the adjustment of the container height so that the drive coupling shows least wear, is a feature that makes it more desirable to have the air cushions effectively below the container rather than ef fectively above the container when the pre-loading is in the form of coil springs, as in FlGS. 3 and 4, or other types of mechanical springs. Such pare-loading applied in a downward direction against the air cushions, as in FIGS.

3 and 4, can be made non-adjustable whereas by reversing removed for relining.

Obviously many modifications and variations of the present invention are possible in the light of the aboye teachings. it is, therefore, to be understood that within the scope of the appended claims the invention may be 13 practiced otherwise than as specifically described. For example, many of the features described above, such as the air cushion feet of FIGS. 7 and 12 the, warning device of FIG. a, the container height adjustment, the quickmounting cover, etc., are suitable for use with vibrators having non-tilting work containers.

What is claimed:

1. An apparatus for subjecting a mass of work articles to vibratory finishing treatment, said apparatus having a supporting framework, a work container resiliently supported by the framework by means of air cushions eifectively below the container, vibratory elements secured to the container for gyration when driven to cause the container to also gyrate, drive mechanism secured to the framework in a fixed position, a generally horizontally extending fiexible drive coupling connecting the drive mechanism to the vibratory elements to cause these elements to be driven by the drive mechanism notwithstanding some difference in height between them and to thereby gyrate the work container while the drive mechanism remains in said fixed position, and height balancing means connected to vary the pressure inside the air cushions and thereby keep said difference in height within bounds for different container loads.

2. An apparatus for subjecting work articles to vibratory finishing treatment, said apparatus having a base, a framework journalled to said base and carrying a work container for tilting at the jonrnalled mounting from an upright position in which the container holds the Work articles to a tilted position at which the work articles are discharged from the container, said work container being resiliently held by and within the framework and carrying vibratory elements to cause the container to gyrate when the elements are driven, a generally horizontally extending jackshaft rotatably mounted on and within the framework opposite the vibratory elements, a flexible drive connecting the jackshaft with the vibratory elements, and an electric motor mounted on and within the framework and coupled to the jackshaft to drive the vibrating elements.

3. The combination of claim 1 in which the electric motor is of the pancake type having a mounting flange along one face of the pancake.

4. The combination of claim 3 in which the electric motor is coupled to the jackshaft by a variable ratio pulley and belt assembly, and the electric motor is mounted between said assembly and the work container.

5. An apparatus for subjecting work articles to gyratory finishing treatment, said apparatus having a container for holding the work articles, the container being held on a supporting framework by air cushions, gyrating means connected to the container for subjecting it to gyratory vibration on the air cushions, the air cushions having means for supplying them with air under difierent pressures, the gyrating means including rotationally mounted elements secured to the container and gyrating with it, and an electric motor connected by a laterally extending yieldable drive connection to the rotationally mounted elements to cause them to effect gyration of the container, the motor being mounted within the supporting framework and isolated from the container gyration by the air cushions.

References Cited by the Examiner UNITED STATES PATENTS 1,173,205 2/16 Mesinger 267-8 2,115,072 4/38 Hunt et a1. 267-15 2,555,688 6/51 Flam 259-72 2,680,535 6/54 Thon 220-32 2,973,606 3/61 Brand-t 51-163 3,071,900 1/63 Balz 51-163 3,103,086 9/63 Balz 51-163 LESTER M. SWINGLE, Primary Examiner.

J. SPENCER OVERHOLSER, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,163,967 January 5, 1965 Ralph W. Moore ified that error appears in the above numbered pat- It is hereby cert he said Letters Patent should read as ent req'liring correction and that t corrected below.

"arrange" read arrangement Column 1, line 47, for

column 14,

line 17, for "sceured" read secured column 9, line 3, for the claim reference numeral "1" read 2 Signed and sealed this 18th day of May 1965.

(SEAL) Attest:

EDWARD J. BRENNER ERNEST W. SWIDER Commissioner of Patents Allesting Officer United States Patent greases GRAPHITE CGATED ABRASWE BELTS Roscoe E. Nafns, 1130 N. 2nd St., Kelso, Wash. No Drawing. Filed Dec. 31, 1962, Ser. No. 248,264 4 Claims. (til. 51-394) This invention relates to an abrasive sander belt having a graphite coating on the surface opposite the abrasive material.

In commercial belt sander operations using a continuous high speed traveling abrasive belt with a backing platen having a low friction material cover, a, considerable amount of static electricity develops which causes dust particles to settle on the sanded article or to float in the air and prevents efiicient removal by the blower system. This is particularly true wherein large panels of 8 feet or more in length are being sanded and the blower system is located at the outlet end of the traveling belt. When such panels are sanded at the end away from the blower system the dust accumulation on the rest of the panel and in the air becomes particularly acute.

Not only does the dust create a hazard for the workman in the area but the fine particles remaining on the panel surface work into balls on subsequent handling and stacking, often causing serious surface blemishes, requiring a down-grading of the costly finished panels and a subsequent lower market price.

Attempts to improve on the efficiency of the dust removal have generally been in the direction of a more efiicient low friction material on the backing platens and/ or grounding the backing platens or other par-ts of the sander equipment. None of these methods has proved satisfactory in removing the dust particles. An object of the present invention, therefore, is to provide for the complete removal of the dust particle from the sanded surface.

Another object of the invention is to provide a means for the elimination of static electricity from the sander belt.

Still another object of the invention is to, create a static-free environment for the sander dust particles to facilitate removal thereof.

These and other objects are accomplished generally by applying a coating of graphite to the sander belt on the surface opposite to that containing the abrasive material. A lubricating, low friction, adherent binder material is first applied to the surface of the belt to be coated with the graphite. Powdered graphite is then applied to the coating of said binder material. Alternatively, the graphite may be mixed with the lubricating, low friction, adherent binder material prior to application to the belt and the resultant mix may then be applied to the surface of the belt opposite the abrasive containing surface.

For ease and clarity in detailing the manner in which the present invention accomplishes these and other object and without limiting ourselves except as stated hereinafter in the claims, the examples and description that follow are given as illustrative of the prepartion of a typical abrasive sander belt having the desired characteristics.

Example I The side opposite the abrasive material on a sander belt measuring 6" by 240" was rubbed with a paraifin Wax block until a total of 4 gms. of wax was applied to the belt. Next, gms. of powdered amorphous graphite was evenly applied to the wax coating and another 2 gins. of parafiin wax was evenly rubbed over the surface.

The coated belt was placed on a standard sanding apparatus and used in sanding 4 foot by 8 foot plywood panels. It effectively eliminated any static electricity causing substantially all of the dust particles to travel along with the moving belt and to be removed by the 2 exhaust system located at one end of the moving sander belt.

Example II To 85.5 gms. of a liquid comprising 60% by weight high boiling (l300 C.) aliphatic hydrocarbons and 40% by weight fluid silicone of the methyl siloxane type was added 90.5 gms. of powdered amorphous graphite and the mixture was stirred to a smooth consistency. A total of 25 gms. of the mixture was evenly applied to the side of a, 6 inch by 240 inches sander belt opposite the abrasive containing side. This belt was immediately used in a sanding operation on 4 foot by 8 foot plywood panels and proved effective in eliminating the heretofore associated static electricity permitting the sanded dust particles to travel along with the traveling belt and to be removed by the exhaust system located at one end of the sander belt.

The particular lubricating, low friction, adherent binder graphite compositions illustrated above proved not only effective upon first using in the sanding operation, but continued to be completely effective throughout the life of the sander belt. Other types of graphite, such as flake or vein were not so effective in that they did not adhere to the binder or the belt under the rugged use conditions associated with such sanding operations. A preferred powdered amorphous graphite for use in the present invention is that identified as Dixon 620, sold by The Dixon Crucible Co., Jersey City, New Jersey.

Silicone fluids also may be mixed directly with the graphite without any hydrocarbon diluents Where coating methods permit use of a more viscous composition.

While specific details of preferred embodiments have been set forth above, it will be apparent that many changes and modifications may be made therein without departing from the spirit of the invention. It will therefore be understood that what has been described herein is intended to be illustrative only, and is not intended to limit the scope of the invention.

" What is claimed is:

1. An abrasive sander belt having a surface coating on the side opposite to that containing the abrasive material comprising a lubricating, 10W-friction, adherent binder and powdered amorphous graphite.

2. The sander belt of claim 1 wherein said binder is selected from the group consisting of paraffin wax and silicone fluids.

3. An abrasive sander belt having a lubricating, lowfriction, adherent surface coating on the side opposite to that containing the abrasive material comprising a mixture of 19.4 parts of silicone fluid, 51.4 parts of powdered amorphous graphite and 29.1 parts of a high boiling aliphatic hydrocarbon diluent.

4. An abrasive sander belt having a thin, lubricating, low-friction, adherent surface coating on the side opposite to that containing the abrasive material including from 0.5 to 1.5 grams of powdered amorphous graphite per square foot of the sander belt.

References Cited by the Examiner UNITED STATES PATENTS 2,356,367 8/44 Wright 252-29 2,624,160 1/53 Harper 51- 141 2,700,623 1/55 Hall 25212 2,854,351 9/58 Wilson 252-29 3,047,526 7/62 Stephens 252'29 X FOREIGN PATENTS 8,598 4/84 Great Britain. of 1884 LESTER M. SWINGLE, Primary Examiner. FRANK H. BRONAUGH, Examiner. 

1. AN APPARATUS FOR SUBJECTING A MASS TO WORK ARTICLES TO VIBRATORY FINISHING TREATMENT, SAID APPARATUS HAVING A SUPPORTING FRAMEWORK, A WORK CONTAINER RESILIENTLY SUPPORTED BY THE FRAMEWORK BY MEANS OF AIR CUSHIONS EFFECTIVELY BELOW THE CONTAINER, VIBRATORY ELEMENTS SECURED TO THE CONTAINER FOR GYRATION WHEN DRIVEN TO CAUSE THE CONTAINER TO ALSO GYRATE, DRIVE MECHANISM SECURED TO THE FRAMEWORK IN A FIXED POSITION, A GENERALLY HORIZONTALLY EXTENDING FLEXIBLE DRIVE COUPLING CONNECTING THE DRIVE MECHANISM TO THE VIBRATORY ELEMENTS TO CAUSE THESE ELE- 